On Thursday 24 June Triple J science segment, a caller asked you about different blood types.

He said that the father determines the blood type of the offspring. This is not correct (if it was, then everyone would have the same blood type, wouldn't we?). For example, my father and my sister are O positive. My mother, my brother and myself are B positive.

There are four blood groups A, AB, B and O. A person who is O negative is a universal donor, and a person who is AB positive is a universal receiver. A person from group A can receive A or O blood, a person from group B can receive B or O blood, a Person from group O can only receive O blood, and a person who is AB can receive any blood group. There is also the Rhesus factor, where blood has it (positive) or does not have it (negative).

The caller asked what happened if the mother has is pregnant with a child with a different blood type to herself, what happened.

I am aware of cases where, a mother is Rhesus (Rh) negative, and has an Rh positive child. With the first pregnancy, it may not cause problems, except during birth when her blood and the baby's blood mix. However, with subsecquent pregnancies, there may be a reaction known as the Rhesus factor, where the mother's antibodies recognise the foetus as an alien body, and attack the foetus. I think what happens then, is the doctor changes the blood type of the child so it is not an alien body. I am not sure how this is done, but there have been such cases in recent times (in the last two or three years).

It would be dangerous if the mother is of, for example, group A and her child is group B. Her antibodies would most likely try and attack the unborn child. If, however, the mother is group A and her child is group O, the anitbodies would not react because it is not an alien body. The only possible danger would then occur during child birth, if there is any exchange of body fluids (this statement is only supposition, not fact).

I hope this helps you out!

Naomi WaresHigh WycombePerth, WA

PS I got this information through the seach engine "Ask Jeeves" and selected the option, "How do I find out about blood types". I am not sure what the exact web site was. - NCW

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From: legolas

25/06/99 23:53:17

Subject: re: Blood Types

post id: 20123

A little bit more perhaps unnecessary information - the blood type follows the dominant and recessive thing too, with A and B both being dominant, and O being recessive. This means for A blood type, you either have AA or AO genes, for B it's BB or BO, for AB it's A and B (oddly enough) and to have O, you need two O's (Which conflicts with nothing, hence isthe universal donor) What i've never understood is the rhesus factor, what controls that?

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From: phoebe

26/06/99 19:05:34

Subject: re: Blood Types

post id: 20242

this is getting stranger by the post, because that's another question we got on our process exam at school (dominant and recessive blood groups). have reason to belive that they are in fact giving us real facts and real science at school. is this legal? i thought they didn't trust us with the real stuff!amazed happiness!phoebe

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From: Marco

26/06/99 20:59:51

Subject: re: Blood Types

post id: 20321

The Rhesus part comes in from another gene altogether...It was discovered first in Rhesus monkeys and then found in humans - thus "Rhesus"...Ummm....it relates to protein substructures on the actual red blood cell - they're like hormone receptors or something, except they don't "receive" anything....just another one of those useless things I suppose..These "bumps" (you could say) on the actual cell means that if someone elses blood gets into you, the body realises and rejects it - that's where the whole "o negative" thing comes in...A person can get another blood type pumped into them for a bit but it becomes useless rapidly, becuase the body rejects it....If you "top up" someone with O neg, there are no Rhesus "bumps" for the body to detect and to kill off...but it'd become less effective after a while, especially if the person is not O type...It is actually better to get the exact type (AB+, A-, etc) that you are because the body doesn't care that your blood came from somewhere else, just as long it is the same type, and same Rhesus type....

By the way, for anyone doing Biology in Yr 12, it is interesting to note that "O" type gene is recessive to A or B, and the Rhesus negative type gene is recessive to Rhesus positive, but the most common blood type in the whole world is "O negative"...This was on an exam I had a while ago and I thought I was being clever by saying that A or B positive was the most common becuase of the dominance factor...wrong...Have a nice day :)

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From: me

4/07/99 16:27:19

Subject: re: Blood Types

post id: 21694

its funny, but in yr 12 biology (and other scince subjects) they tell you alot of teh wrong information just because its easier to explain that the right stuff. being a 3rd yr biotech student i've found this to be the case with various subjects (all of which i cant really remember right now being hung over and all)

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